Current supply arrangement for use in telephone systems



Jan. 14, 1941. E. FRYDMAN I 2,228,449

CURRENT SUPPLY ARRANGEMENT FOR USE IN TELEPHONE SYSTEMS Filed April 14,;938

aflnlrwvw 7 m kz W 12 W n12 QA G8 I GC I' 1- 1 YA I YB I Yc k3 13 ms l 1 i 1 l i I I 1' IHII K qkilIP-U 'IH k M k1 21 m1 \0 ll ,4 I I I I FIGI I I z i i Li 5 I a M 1 i I I k A B 4 l INVENTOR EMANUEL FRYDMAN Patented Jan. 14, 1941 CURRENT SUPPLY ARRANGEMENT FOR USE IN TELEPHONE SYSTEMS Emanuel Frydman, Liverpool, England, assignor to Associated Telephone & Telegraph Company, Chicago, 111., a corporaticn of Delaware Application April 14, 1938, Serial No. 201,899 In Great Britain May 20, 1937 7 Claims. (Cl. 17197) The present invention relates to current supply with a heavy copper collar around its core; the arrangements for telephone signalling systems collars, which will hereinafter be referred to as and is particularly concerned with systems in slugs, make the relays slow to release in the wellwhich in addition to the normal operating batknown manner. Since no two relays even if they tery potential, reverse and augmented potentials are of identical construction and loading have are required for signalling or metering purposes. precisely the same operating characteristics, it Generally this requirement is met by the prois found that after a few initial operations the vision of a small auxiliary battery in addition relays become out of step sufficiently to settle to the normal main operating battery. down to a sustained cyclic operation as indi- 10 In small exchanges however such as are incated in Fig. 2,

stalled in rural areas the provision of another This shows three complete cycles of operation battery of the secondary cell type with the necon the basis that a heavy single line indicates essary charging arrangements considerably inthe period over which each relay is operated due creases the prime cost while the use of dry cells to the energisation of its winding whilst a double for this purpose is objectionable due to the line indicates the period over which each relay periodic replacements required. The main batremains operated due to its slug after the dist-ery itself cannot be used for supplying pqtenconnection of its energising circuit. It will be tial of opposite polarity since it is desirable for seen from reference to the circuit diagram of other reasons for one pole to be permanently Fig. 1 that if it is assumed that a cycle comearthed. The object of the invention is to obmenses on the release of relay L, the winding of tain an auxiliary potential from the normal operrelay K will be energised and this relay on operating battery by making use of a simple conating quickly disconnects the energising circuit verting arrangement of generally known type. for relay M which now holds operated for 21 According to the invention in a current supply further period due to its slug. On the release of 5 arrangement for a small telephone exchange a relay M, a circuit is completed to energise the potential independent of the exchange battery is winding of relay L which operates quickly and obtained by the use of a plurality of large cap-acdisconnects the energising circuit of relay K. ity condensers in conjunction with switching ar- On the release of this relay after its slow release rangements whereby the condensers are cyclically period, which is substantially equal to that of charged from the exchange battery and cyclically relay M, the latter relay is again operated where discharged to supply the required potential. upon relay L commences its slow release period.

The invention will be better understood. from On the release of relay L, relay K is again operthe following description of one method of carryated and the next cycle commences and carries ing it into effect, which should be taken in conthrough in the manner described. junction withthe accompanying drawing com- It will be appreciated that the length of each prising Figs. 1 and 2. Fig. 1 is a circuit diagram cycle may be readily varied by altering the size or of the converting arrangement according to the position of the slugs on the relays or by providinvention. Fig. 2 is a time graph schematically ing other means of obtaining operating or release illustrating the cyclic operation of the convertlags.

40 ing arrangement. 7 It will be seen that during practically the whole Referring first to Fig. l, the three relays K, of each cycle two relays are operated and one L and M are arranged in a continuous chain to is normal and as a result two condensers are operate and release in cyclic order and ensure connected to the discharge circuit while one is by means of their contacts that at all times being charged. For example, during the period during their operation one of the condensers QA, relay L is normal, a circuit is completed to charge QB and QC, which are preferably of the electrocondenser QB from earth, armature Z3, resistance lytic type, is being charged whilst the other two YB, condenser QB, armature l2, resistance YD to are connected to a discharge circuit. the normal main battery while at the same time It is intended that a contact such as it] would the charged condensers QA and QC are connected be closed when the special potential, in this case over the operated armatures of relays K and M booster battery, was required. Thereupon the respectively to a lead extending to a distribution three relays K, L and M are operated and at bar I I. A typical relay X, arranged by means their armatures ll, ml and kl break the energisof a rectifier to operate on a reverse potential ing circuits so that they commence to release and only, is shown, by way of example connected to then re-operate. Each of the relays is provided this bar. On the release of relay M, condenser Q is put on charge. On the operation of relay L the fully charged condenser QB is connected in parallel with condenser QA and this condition remains until relay K releases when another changeover is eifected.

The cycle time is arranged to be a minimum consistent with the satisfactory charging of the condensers so that with a given continuous discharge load the condenser capacities required to maintain a predetermined range of potential will be as small as possible.

During such times as the converting arrangement is not in use, that is to say no contacts such as Ii) are closed, all the condensers are charged fully over resting contacts of the relays K, L and M in readiness for the next demand.

Resistances YA to YC are of low value and are merely inserted as current limiting resistances in case a charged condenser is accidentally shortcircuited by way of contacts of one of the relays K, L and M. Resistance YD is utilised to regulate the charging rate.

It will be understood that the battery syinbols shown connected to the windings of relays K, L and M represent the main operating battery and are only shown separately for convenience.

I claim:

1. A current supply circuit comprising, a direc current source, a plurality of condensers, a loa circuit, a series of slow acting relays, means for connecting said relays to said source to operate said relays in cyclic permutation, each relay alternately connecting a different one of said condensers to the source and to the load circuit.

2. In combination, a relay chain, each relay in said chain having a contact to control the operation of the next relay in said chain, thereby causing said chain of relays to operate continuously in cyclic permutation, a plurality of condensers, the different ones of said condensers corresponding respectively to the different ones of the relays in said chain, a source of charging current for said condensers, a discharge circuit common to all of said condensers, and contacts on each relay in said chain operated to connect the condenser corresponding to that relay alternately to said source and said discharge circuit.

3. In an energy converting arrangement, a plurality of relays, means for alternately energizing and deenergizing each said relay in such timed relationship to the energizations and deenergizations of the others of said relays that at every instant at least one of the relays is energized and at least one of the relays is deenergized, a condenser individual to each relay, a direct current source, a load circuit, and contacts on each relay connecting that relays individual condenser to said source when the relay is in one of its positions and to said load circuit when the relay is in the other of its positions.

4, In combination, a plurality of condensers, a source of charging current for said condensers, a discharge circuit common to all of said condensers, means operated to connect said condensers to said source in cyclic permutation, said means effective also after each condenser has been charged from said source to disconnect that condenser therefrom and to connect it transitorily to said discharge circuit, said condensers thereby being connected to said discharge cir cuit in the same sequence as they are connected to said source, and one of said condensers always being charged from said source while another is being discharged over said circuit.

5. In an energy converting arrangement, a source of direct current, a load, a plurality of condensers, means operated to connect each said condenser alternately to said source to charge said condenser and to said load to discharge said condenser, said means effective to disconnect each condenser from said load when that condenser is connected to said source and to disconnect each condenser from said source when that condenser is connected to said lead, whereby none of the condensers is at any time connected both to said source and to said load, said means controlling the alternate connection to said source and said load of all of said condensers and effective to maintain the connections of the respective condensers to said source in such timed relationship that at every instant at least one of said condensers is connected to said source.

6. In an energy converting arrangement, a source of direct current, a load, a plurality of condensers, means operated to connect each said condenser alternately to said source to charge said condenser and to said load to discharge said condenser, said means effective to disconnect each condenser from said load when that condenser is connected to said source and to disconnect each condenser from said source when that condenser is connected to said load, whereby none of the condensers is at any time connected both to said source and to said load, said means controlling the alternate connection to said source and said load of all of said condensers and effective to maintain the connections of the respective condensers to said load in such timed relationship that at every instant at least one of said condensers is connected to said load.

'7. In an energy converting arrangement, a source of direct current, a load, a plurality of condensers, means operated to connect each said condenser alternately to said source to charge said condenser and to said load to discharge said condenser, said means effective to disconnect each condenser from said load when that condenser is connected to said source to disconnect each condenser from said source when that condenser is connected to said load, whereby none of the condensers is at any time connected both to said source and to said load, said means controlling the alternate connection to said source and said load of all of said condensers and effective to maintain the connections of the respective condensers to said source and said load in such timed relationship that at every instant at least one of said condensers is connected to said source and at least one of said condensers is connected to said load.

EMANUEL FRYDMAN. 

